According to the Associate Press, candidates running for Pennsylvania governor have released their tax returns going back to the 1990s.

But this year, Republican gubernatorial candidate Scott Wagner has not, leading to an earful from Pennsylvania Democrats.

On Tuesday, state Senate Minority Leader Jay Costa (D-Forest Hills) held a press conference at the Allegheny County Courthouse asking Wagner to release his tax returns. Costa joins Gov. Tom Wolf’s campaign in calling for Wagner to release his tax returns.

“Why hasn’t Scott Wagner released his tax returns?” asked Costa. “We need him to be open and transparent. A gubernatorial candidate should release their tax returns.”

There is no state law requiring candidates to release their tax returns. In March, calls came for the Republican gubernatorial candidates to release their returns to no avail. Wagner became a millionaire by running his York County waste-management business, Penn Waste.

Another wealthy politician, President Donald Trump, famously never released his tax returns prior to the 2016 election, despite calls from advocates, voters, and political leaders.

When asked if voters actually cared about seeing tax returns, Costa said that many voters do care and releasing returns would provide those voters an opportunity to make an informed decision.

In a June article in PennLive, Wagner spokesperson Andrew Romeo said it was hypocritical for Gov. Wolf and top Democrats to demand transparency over tax returns, since the state has not released details about the state’s Amazon HQ2 proposal. Romeo did not indicate if Wagner would release his returns.

"Scott has been transparent by meeting every single disclosure requirement. Governor Wolf is hiding from Pennsylvanians how much of their hard earned dollars he wants to give to Amazon,” said Romeo. "So if Governor Wolf wants to make this race a referendum on transparency, we like our chances at the ballot box."

Costa said Wagner’s role as Penn Waste CEO could use some scrutiny, given Wagner is running for statewide office and his company has contracts with municipal governments.

“From a business-interest point of view, voters should be able to assess the candidates,” says Costa.

In 2016, Wolf released his 2015 tax returns at the call of advocates. Those showed he earned $4.5 million in 2015 thanks to his private business. Wolf donates his governor's salary to charity. The Wolf campaign said Wolf plans to release his 2017 tax return this fall, and that his returns from 2010-2016 have already been made public.